Babies who do not eat much in the first fortnight of life may be set up for better heart health throughout life.

Trying to get a new baby to put on weight is a natural parental desire, but research suggests that very rapid weight gain very early in life may not necessarily be a good thing.

A study carried out at the Institute of Child Health in London found that babies who received a "low nutrient" diet rather than a "nutrient rich" diet in their first days were healthier as adolescents.

The message is not to restrict food in the first few weeks, but to encourage breastfeeding

Dr Atul Singhal, Institute of Child Health

They were less likely to have "insulin resistance", a symptomless condition strongly associated with an increased risk of diabetes later in life.

The researchers say that it does not mean that new parents should actively restrict the diets of their newborns, but provides more evidence that breastfeeding is the best possible way to feed them.

New mothers usually produce very small amounts of milk in the first few days after birth, and even healthy babies tend to actually lose weight to start with.

But the study suggests this is certainly not harmful, and may even be beneficial in the longer term. It warned parents against "overfeeding" newborn babies by giving them large amounts of formula feed.

"The message is not to restrict food in the first few weeks, but to encourage breastfeeding."

The study was carried out on a sample of premature babies, but Dr Singhal said the findings were likely to apply to full-term babies, as this was the case in many other animals.

He said: "We would not encourage any different treatment of premature babies.

"There are good reasons why underfeeding of low birthweight babies is not appropriate."

Lifestyle factors

Professor Michael Lean, Chair of Human Nutrition at the University of Glasgow, told BBC News Online that even if a child grew quickly during the first weeks and went on to develop insulin resistance, they were not fated to develop diabetes, provided they were not overweight in adulthood and led a reasonably healthy lifestyle.

He said: "Ultimately it requires that the person gets fat.

"If you remain at the ideal body mass throughout your adult life you are much less likely to have a problem."

He said that parents were frequently anxious about the amount their children were eating.

He said: "As long as they are putting on some weight, there is no problem."